Joint Fullband-Subband Modeling for High-Resolution SingFake Detection
Authors: Xuanjun Chen, Chia-Yu Hu, Sung-Feng Huang, Haibin Wu, Hung-yi Lee, Jyh-Shing Roger Jang
Organizations: Graduate Institute of Communication Engineering, National Taiwan University · Department of Computer Science and Information Engineering, National Taiwan University · NVIDIA Taiwan · Independent Researcher · NTU Artificial Intelligence Center of Research Excellence, National Taiwan University
Rapid advances in singing voice synthesis have increased unauthorized imitation risks, creating an urgent need for better Singing Voice Deepfake (SingFake) Detection, also known as SVDD. Unlike speech, singing contains complex pitch, wide dynamic range, and timbral variations. Conventional 16 kHz-sampled detectors prove inadequate, as they discard vital high-frequency information. This study presents the first systematic analysis of high-resolution (44.1 kHz sampling rate) audio for SVDD. We propose a joint fullband-subband modeling framework: the fullband captures global context, while subband-specific experts isolate fine-grained synthesis artifacts unevenly distributed across the spectrum. Experiments on the WildSVDD dataset demonstrate that high-frequency subbands provide essential complementary cues. Our framework significantly outperforms 16 kHz-sampled models, proving that high-resolution audio and strategic subband integration are critical for robust in-the-wild detection.
Figures & tables
Figure 1: Comparison of audio spectral coverage under different sampling rates. Existing systems typically process 16 kHz sampled audio, restricting them to the speech-critical band (0–8 kHz) and discarding high-frequency details. In contrast, our approach utilizes 44.1 kHz audio to cover the full spectral range (0–22.05 kHz). This preserves extended harmonics and breath textures essential for detecting sophisticated singing forgeries that are mathematically invisible at lower sampling rates.
Figure 2: The overview of our proposed Sing-HiResNet framework. The framework is implemented in two stages: Phase 1 establishes the backbone for fullband and subband expert models, while Phase 2 facilitates their integration through various joint fusion processes.
Model
Subband (kHz)
Valid
Test A
Test B
Fullband N=1
FB [0.0,22.0]
0.00–22.05
0.66
2.31
10.79
Subband N=2
SB [0.0,11.0]
0.00 – 11.03
1.39
2.81
22.01
SB [11.0,22.0]
11.03 – 22.05
1.71
5.66
15.32
SB-Concat-2
0.09
3.13
16.29
Table 1: EER (%) of subband expert models across different subband partition configurations. Model names indicate approximate frequency ranges for readability, while the subband (kHz) column reports the exact band boundaries. SB-Concat- N denotes the feature-level concatenation model combining all subbands in the same configuration.
Selected Model Pool P
Aggregation
Concatenation
Interaction
Distillation *
FB
SB L
SB M
SB H
Test A
Test B
Test A
Test B
Test A
Test B
Test A
Test B
Pool Pa
✓
✓
1.73
10.79
2.95
15.53
2.99
15.32
1.83
11.00
Pool Pb
✓
✓
2.56
11.21
2.95
20.82
3.24
16.29
3.13
12.19
Pool Pc
✓
✓
2.28
10.79
2.85
16.50
3.02
15.32
2.17
10.79
Pool Pd
✓
✓
✓
1.87
9.82
3.57
19.64
3.02
16.50
1.87
12.19
Pool Pe
✓
✓
✓
1.73
8.84
3.43
24.16
3.75
7.45
1.65
9.06
Table 2: EER (%) of the proposed integration framework across different component configurations.
Figure 3: EER (%) results across two categorization schemes. The left columns present a method-centric view to highlight frequency impact, while the right columns provide a condition-centric comparison of integration strategies across Test A and Test B.
Figure 4: Grad-CAM visualizations of expert and distilled models for bonafide and deepfake samples, featuring (a) single-teacher (Low) and (b) dual-teacher (Low/Mid-High) distillation. White dashed lines marking corresponding subband boundaries.
Notation
Description
Methods
Selected Model Pool P
EER (%)
FB D-LM
FB
SB L
SB M
Test A
Test B
(a)
FB D-LM
Pool Pe in Table 2
Distillation *
✓
✓
✓
1.65
9.06
(b)
FB A-LM
Pool Pe in Table 2
Aggregation
✓
✓
✓
1.73
8.84
(c)
FB SA-D-LM
Subband
Aggregation
✓
✓
✓
1.73
12.19
(d)
FB FSA-D-LM
Fullband-Subband
Aggregation
✓
✓
✓
✓
1.58
8.77
* FB is the fullband student model, SB ∼ are the subband expert teacher models.
Table 3: EER (%) of cross-integration strategies. SB L and SB M denote expert models for 0–11 kHz and 11–16.5 kHz bands, respectively.
Models
Backbone
fs
Test A (CI)
Test B (CI)
Baseline1
Wav2vec
16
6.09
24.09
Baseline2
Raw
16
8.84
26.11
PDL
Ensemble
16
5.80
22.01
NTU
SingGraph
16
4.31
31.82
IMS-SCU
WavLM
16
3.54
15.32
IMS-SCU
Ensemble
16
2.70
12.95
Table 4: Performance comparison on WildSVDD dataset, where fs denotes sampling rate (kHz). Results are presented in Equal Error Rate (EER, %) with 95% Confidence Intervals (CI).
With rapid advances in audio-visual generative models, reliable forgery detection becomes increasingly critical. Existing methods for audio-visual deepfake detection typically rely on cross-modal inconsistencies. In singing, rhythmic vocalization weakens this coupling and introduces a nontrivial domain shift, substantially degrading detection performance. We construct the Singing Head DeepFake (SHDF) dataset using rhythm-aware generative models to fill the gap in singing benchmarks. To cope with cross-scenario domain shifts, we propose a Text-guided Audio-Visual Forgery Detection (T-AVFD) framework that generalizes across both talking and singing scenarios. T-AVFD comprises a facial authenticity pattern learner and a multi-modal differential weight learning module. The pattern learner aligns facial features with multi-granularity textual descriptions to learn generalizable authenticity patterns. The weight learning module preserves intrinsic audio-visual consistency and adaptively integrates it with authenticity patterns via differential weighting. Extensive experiments on multiple talking head deepfake datasets and SHDF show consistent improvements over existing baselines and strong robustness under diverse perturbations.
Ke Liu, Jiwei Wei, Wenyu Zhang +5
Center for Future Media, School of Computer Science and Engineering, University of Electronic Science and Technology of China, Chengdu, China
Recent Singing Voice Synthesis (SVS) advances enable highly realistic but potentially malicious AI covers, making singing voice deepfake detection (SVDD) crucial. Self-Supervised Learning (SSL)-based detectors achieve state-of-the-art performance by fine-tuning speech SSL backbones to capture singing-specific spoof artifacts. Existing adversarial attacks often fail against SSL-SVDD, creating a false impression of inherent robustness. We reveal this stems from two challenges. First, at the objective level, attacks optimize cross-entropy on local surrogates, crossing surrogate-specific boundaries rather than suppressing shared spoof evidence. Second, at the method level, attacks follow the surrogate's dominant gradient direction. In SSL-SVDD, this aligns with fine-tuned artifact-sensitive directions, limiting transferability to unseen detectors - a geometric failure we term the Linearity Trap. To properly evaluate robustness, we propose MARS (Meta-Adversarial Regression of Semantics), a transfer-based black-box framework tailored to SSL-SVDD. Structurally, MARS shifts to hypothesis-evidence manipulation by constructing a natural semantic anchor from the pre-trained SSL space and an artifact anchor from the fine-tuned space. Algorithmically, MARS escapes the Linearity Trap via bi-level optimization: the inner stage induces tangential exploration, while the outer stage guides the audio toward the natural semantic manifold. Experiments on the CtrSVDD benchmark show MARS improves Attack Success Rate (ASR) in in-distribution transfer (13%), out-of-distribution transfer (10%), and cross-task evaluation (36%), highlighting the urgent need for robust SVDD systems.
Yifan Liao, Yule Liu, Zhen Sun +5
Wuhan University · The Hong Kong University of Science and Technology (Guangzhou)
Recently, speech deepfake detection (SDD) has achieved significant progress. However, its robustness evaluation remains largely confined to controlled additive noise scenarios, lacking systematic investigation of the complex distortions introduced by acoustic front-end (AFE) processing pipelines in real-world deployments. In this work, we simulate a unified AFE pipeline comprising acoustic echo cancellation, noise suppression, automatic gain control, and voice activity detection (VAD), and conduct a comprehensive evaluation of current state-of-the-art models. The results show that the nonlinear and time-frequency coupled distortions introduced by AFE significantly degrade detection performance. To address this issue, we propose a Time-Frequency Consistency Learning (TFCL) framework, which aims to learn invariant spoofing representations that remain stable before and after AFE processing. We observe that AFE not only introduces temporal misalignment (e.g., segment-level shifts caused by VAD), but also weakens or distorts critical frequency-domain cues. To this end, TFCL employs an attention-driven soft alignment mechanism to capture cross-temporal dependencies, along with frequency-domain structural consistency constraints to enforce feature invariance. As a result, the model is able to maintain stable representations under both temporal perturbations and spectral distortions. Extensive experimental results demonstrate that the proposed method effectively mitigates the performance degradation caused by AFE processing, significantly improving the robustness of SDD in real-world scenarios. The code is available at https://github.com/JunXue-tech/TFCL.
Jun Xue, Zhuolin Yi, Yanzhen Ren +6
School of Cyber Science and Engineering, Wuhan University Wuhan, China · Wuhan University Wuhan, China · Tongji University ShanghaiU, China